Preservation of minimally processed 'aurora-1' peaches using additives

'Aurora-1' peaches establishes an interesting alternative as a minimally processed product, due to its characteristics like flavor, color, smell, and also because of its handling resistance. However, it has a short shelf life after a fresh-cut due to enzymatic browning and stone cavity collapse. The main purpose of this research was to test the additive with antioxidant effect to prevent browning in minimally processed 'Aurora-1' peaches. The minimal processing consists of washing, sanitizing, peelings and fruit stone extraction. After that, longitudinal cuts were made to obtain eight segments per fruit. The slices were immersed into the following treatment solutions: control (immersion in 2% ascorbic acid); 2% ascorbic acid + 2% calcium chloride; 1% sodium isoascorbate; 1% citric acid; 1% L-cysteine hydrochloride. The products were placed into rigid polystyrene trays branded MEIWA M-54, covered with 14 µm PVC film (OmnifilmTM) and kept in cold storage at 3ºC ± 2ºC and 65% RH for twelve days, and evaluated each three days. Appraised variables were appearance, soluble solids, titratable acidity, soluble carbohydrates and reducing sugars, total and soluble pectin, ascorbic acid, and peroxidase and polyphenol oxidase enzyme activity. L-cysteine gave to the minimally processed products a shelf life of twelve days, limmited by off-flavor. The treatment with ascorbic acid was efficient to maintainthe ascorbic acid content, with a shelf-life of nine days, limited by enzymatic browning.

Painatuksen UV-stabiilisuuden optimointi fenolihartsatussa paperissa

Tässä diplomityössä tutkittiin painetun paperin ja siitä fenoliformaldehydihartsilla impregnoimalla valmistetun pinnoituskalvon UV-stabiilisuuden parantamis-mahdollisuuksia. Työn kirjallisuusosassa käsitellään painetun pinnoituskalvon valmistusprosessia ja painatuksen UV-valonkestoon vaikuttavia tekijöitä. Painovärin pigmentti, sen määrä ja käsittely, painovärin sideaine sekä fenoliformaldehydihartsi ja sen lisäaineet vaikuttavat pinnoitetun betonoimisvanerin säänkesto-ominaisuuksiin. Erilaisilla epäorgaanisilla valkoisilla pigmenteillä ja kidemuodoilla on erilainen UV-valonkesto ja taitekerroin. Päällystämällä titaanidioksidi esimerkiksi alumiini- tai zirkoniumoksideilla sen UV-valonkestoa voidaan parantaa merkittävästi. UV-hajoaminen voidaan havaita painetun pinnoitteen liituuntumisena. Liituuntumista voidaan pitää veden ja hapen välisenä reaktiona, jota titaanidioksidi ja UV-säteily katalysoivat. Sen takia myös muiden valkoisten epäorgaanisten pigmenttien ominaisuuksia ja käyttöä selvitettiin. Kokeissa käytettiin yhdeksää eri painoväriä, kahta eri paksuista paperia ja kahta eri tyyppistä hartsia. Painovärejä ohennettiin vedellä ja paperin painopuolta vaihdeltiin. Kaikissa painatuksissa käytettiin kolmea eri rasterointiasteen laattaa, jolloin painovärin määrää paperissa saatiin vähennettyä. Painetuista papereista mitattiin densiteetti, värimäärä, pisara-absorptio vedellä ja kontaktikulma hartsilla. Myös painovärin tunkeumaa selvitettiin paperin poikkileikeistä tehtyjen SEM-kuvien avulla. Painetut paperit impregnoitiin fenoliformaldehydihartsilla kalvoksi. Pinnoituskalvot puristettiin vanerin pinnalle laboratoriopuristimella. Koekappaleet altistettiin UV-valolle, sateelle ja pakkaselle sääkaapissa 400 h ajan, mikä vastaa noin 1,5 vuotta ulkona Suomen oloissa. Kappaleista mitattiin kiilto, värinmuutos ja liituuntuminen. Pinnoitteen liituuntumista tapahtui vähiten niissä koepisteissä, joissa painatus oli tehty 30 % rasteroidulla laatallaSäänkestävä TiO2 osoittautui hyväksi, mutta myös ZnO-pigmentillä saatiin hyviä tuloksia. ZnO-koepisteessä liituuntumisreaktio ei ole niin voimakkaasti katalysoitu kuin TiO2-koepisteissä. Paksun paperin painatuspuolella näytti olevan merkitystä säänkestoon. Huopapuolelle painettuna pinnoitteen liituuntuminen oli vähäisempää

Genome sequence of the Drosophila melanogaster male-killing Spiroplasma strain MSRO endosymbiont.

Spiroplasmas are helical and motile members of a cell wall-less eubacterial group called Mollicutes. Although all spiroplasmas are associated with arthropods, they exhibit great diversity with respect to both their modes of transmission and their effects on their hosts; ranging from horizontally transmitted pathogens and commensals to endosymbionts that are transmitted transovarially (i.e., from mother to offspring). Here we provide the first genome sequence, along with proteomic validation, of an endosymbiotic inherited Spiroplasma bacterium, the Spiroplasma poulsonii MSRO strain harbored by Drosophila melanogaster. Comparison of the genome content of S. poulsonii with that of horizontally transmitted spiroplasmas indicates that S. poulsonii has lost many metabolic pathways and transporters, demonstrating a high level of interdependence with its insect host. Consistent with genome analysis, experimental studies showed that S. poulsonii metabolizes glucose but not trehalose. Notably, trehalose is more abundant than glucose in Drosophila hemolymph, and the inability to metabolize trehalose may prevent S. poulsonii from overproliferating. Our study identifies putative virulence genes, notably, those for a chitinase, the H2O2-producing glycerol-3-phosphate oxidase, and enzymes involved in the synthesis of the eukaryote-toxic lipid cardiolipin. S. poulsonii also expresses on the cell membrane one functional adhesion-related protein and two divergent spiralin proteins that have been implicated in insect cell invasion in other spiroplasmas. These lipoproteins may be involved in the colonization of the Drosophila germ line, ensuring S. poulsonii vertical transmission. The S. poulsonii genome is a valuable resource to explore the mechanisms of male killing and symbiont-mediated protection, two cardinal features of many facultative endosymbionts. IMPORTANCE: Most insect species, including important disease vectors and crop pests, harbor vertically transmitted endosymbiotic bacteria. These endosymbionts play key roles in their hosts' fitness, including protecting them against natural enemies and manipulating their reproduction in ways that increase the frequency of symbiont infection. Little is known about the molecular mechanisms that underlie these processes. Here, we provide the first genome draft of a vertically transmitted male-killing Spiroplasma bacterium, the S. poulsonii MSRO strain harbored by D. melanogaster. Analysis of the S. poulsonii genome was complemented by proteomics and ex vivo metabolic experiments. Our results indicate that S. poulsonii has reduced metabolic capabilities and expresses divergent membrane lipoproteins and potential virulence factors that likely participate in Spiroplasma-host interactions. This work fills a gap in our knowledge of insect endosymbionts and provides tools with which to decipher the interaction between Spiroplasma bacteria and their well-characterized host D. melanogaster, which is emerging as a model of endosymbiosis.

Controle da maturação de caqui 'Fuyu' com aplicação de aminoetoxivinilglicina e 1-metilciclopropeno

O armazenamento de caquis é uma ferramenta importante na manutenção da qualidade e no prolongamento da oferta do fruto após a colheita. O objetivo deste trabalho foi avaliar o efeito da aplicação de AVG em pré-colheita, e do 1-MCP, em pré e pós-armazenamento, sobre a manutenção da qualidade pós-colheita e seu efeito na incidência de distúrbios em caquis 'Fuyu' armazenados em atmosfera controlada a -0,5 ºC e transferidos a condição de ambiente (20 ºC) por 6 dias. Os tratamentos foram: [1] controle; [2] aplicação de AVG (123 g ha-1); [3] aplicação de 1-MCP (1,0 µL L-1) em pré-armazenamento; [4] aplicação de AVG e 1-MCP em pré-armazenamento; [5] aplicação de 1-MCP em pós-armazenamento; [6] aplicação de AVG e 1-MCP em pós-armazenamento. Os frutos foram avaliados quanto à qualidade na ocasião da colheita, visando à caracterização do lote e, após quatro meses de armazenamento a -0,5 ºC e mais seis dias a 20 ºC, quanto à firmeza da polpa, pH, coloração da casca, índices de amaciamento e de escurecimento, teores de sólidos solúveis e de acidez titulável, respiração, produção de etileno, além da atividade da enzima ACC oxidase. Os resultados indicaram que a aplicação de 1-MCP em pré ou em pós-armazenamento foi eficiente em conter o amaciamento da polpa de caquis 'Fuyu' previamente armazenados em atmosfera controlada a -0,5 ºC e mantidos a 20 ºC por seis dias. Todavia, o uso deste fitorregulador em pré-armazenamento ocasionou maior escurecimento da epiderme. O uso de AVG em pré-colheita não retardou a maturação de caquis 'Fuyu' armazenados na mesma condição.

Ácido 2,3,5-tri-iodobenzoico (TIBA) na micropropagação de abacaxizeiro 'IAC Gomo-de-Mel'

O abacaxi 'IAC Gomo-de-Mel' é uma espécie economicamente importante devido a diversas características sensoriais. Uma das técnicas para obter maior número de plantas é a micropropagação. Assim, o objetivo deste trabalho foi avaliar a ação do TIBA (ácido 2,3,5-tri-iodobenzoico) na formação de brotos e raízes do abacaxizeiro 'IAC Gomo-de-Mel', assim como possíveis alterações na morfologia de tecidos foliares. Foram utilizados segmentos das gemas da coroa de abacaxi, com aproximadamente 1 cm, oriundos de cultivo em meio líquido, suplementadas com 1,0 mg L-1 BAP+ 0,5 mg L-1 NAA , sendo posteriormente inoculados em meio MS líquido contendo diversas concentrações de TIBA, em condição de luz e temperatura controladas, implantando 3 diferentes experimentos para as análises biométrica, bioquímica e anatômica. Os experimentos foram implantados em delineamento experimental inteiramente ao acaso, com 8 tratamentos, com 4 repetições para as análises biométricas e 5 repetições para a bioquímica e anatômica. Ao final de 60 dias, foram avaliados o número e o comprimento das brotações, o comprimento da planta-mãe e o número de raízes. A análise da atividade de AIA-oxidase foi realizada no dia da instalação do experimento e aos 15; 30; 45 e 60 dias de cultivo. Conclui-se que o TIBA isoladamente não induz brotações. A redução na atividade da AIA-oxidase foi relacionada com a emissão de novas raízes, e o aumento na espessura dos tecidos foliares ocorreu após aplicação exógena de TIBA, em abacaxizeiro in vitro.

ATIVIDADE RESPIRATÓRIA EM MITOCÔNDRIAS ISOLADAS DA POLPA DO MAMÃO UENF/CALIMAN 01 E TAINUNG 01 NA CONSERVAÇÃO DO FRUTO EM PÓS-COLHEITA

Este trabalho teve como objetivo comparar a atividade respiratória em mitocôndrias isoladas e os atributos físicos e químicos da polpade dois híbridos de mamão, UENF/Caliman01 (UC01) e Tainung01,durante o amadurecimento dos frutos. Oamadurecimento dos frutos não mostrou diferenças significativas entre os genótipos na luminosidade (L), no croma (C) e no ângulo hue da casca. A perda de massa (PM)e as firmezas do fruto (FF) e domesocarpo (FM) diferiram entre os genótipos, sendo que a FF e a FM diminuíram com o tempo após a colheita,ao contrário da PM, que aumentou no mesmo período. A atividade respiratória nas mitocôndrias isoladas mostrou diferenças entre os genótipos quanto à respiração total (RT), sendo maior e decrescente no Tainung01 e constante no UC01 durante o amadurecimento dos frutos. Durante esse período, verificou-se que a participação da via oxidase alternativa (AOX) foi crescente, contra uma participação decrescente da via citocromo oxidase (COX) em ambos os híbridos, indicando um crescente desacoplamento das mitocôndrias, o que pode estar associado às rápidas transformações bioquímicas que acarretam a senescência do órgão. A partir desses resultados, sugere-se investigar materiais genéticos com menor atividade AOX, ou formas de minimizar a atividade respiratória nos frutos em pós-colheita. A AOX apresentou alta correlação positiva com a PM e negativa com a FF e a FM. O inverso foi observado para COX. A RT apresentou correlação positiva apenas com a FM. As correlações apontam a viabilidade de estimar a atividade respiratória por meiode análises mais simples, como a PM, a FF e a FM, facilitando a pesquisa na área.

Photocatalytic Activity of Nanostructured Anatase Coatings Obtained by Cold Gas Spray

This article describes a photocatalytic nanostructured anatase coating deposited by cold gas spray (CGS)supported on titanium sub-oxide (TiO22x) coatings obtained by atmospheric plasma spray (APS) onto stainless steel cylinders. The photocatalytic coating was homogeneous and preserved the composition and nanostructure of the starting powder. The inner titanium sub-oxide coating favored the deposition of anatase particles in the solid state. Agglomerated nano-TiO2 particles fragmented when impacting onto the hard surface of the APS TiO22x bond coat. The rough surface provided by APS provided an ideal scenario for entrapping the nanostructured particles, which may be adhered onto the bond coat due to chemical bonding; a possible bonding mechanism is described. Photocatalytic experiments showed that CGS nano-TiO2 coating was active for photodegrading phenol and formic acid under aqueous conditions. The results were similar to the performance obtained by competitor technologies and materials such as dip-coating P25 photocatalysts. Disparity in the final performance of the photoactive materials may have been caused by differences in grain size and the crystalline composition of titanium dioxide.

L-tyrosine and nitric oxide synergize to prevent cytotoxic effects of superoxide.

We found previously that the nitric oxide donor DEA/NO enhanced lipid peroxidation, DNA fragmentation, and cytotoxicity in human bronchial epithelial cells (BEAS-2B) when they were cultured in LHC-8 medium containing the superoxide-generating system hypoxanthine/xanthine oxidase (HX/XO). We have now discovered that DEA/NO's prooxidant action can be reversed by raising the L-tyrosine concentration from 30 to 400 microM. DEA/NO also protected the cells when they were cultured in Dulbecco's Modified Eagle's Medium (DMEM), whose standard concentration of L-tyrosine is 400 microM. Similar trends were seen with the colon adenoma cell line CaCo-2. Since HPLC analysis of cell-free DMEM or LHC-8 containing 400 microM L-tyrosine, DEA/NO, and HX/XO revealed no evidence of L-tyrosine nitration, our data suggest the existence of an as-yet uncharacterized mechanism by which L-tyrosine can influence the biochemical and toxicological effects of reactive nitrogen species.

Transition mutation in codon 248 of the p53 tumor suppressor gene induced by reactive oxygen species and a nitric oxide-releasing compound.

Exposing the human bronchial epithelial cell line BEAS-2B to the nitric oxide (NO) donor sodium 1-(N,N-diethylamino)diazen-1-ium-1, 2-diolate (DEA/NO) at an initial concentration of 0.6 mM while generating superoxide ion at the rate of 1 microM/min with the hypoxanthine/xanthine oxidase (HX/XO) system induced C:G-->T:A transition mutations in codon 248 of the p53 gene. This pattern of mutagenicity was not seen by 'fish-restriction fragment length polymorphism/polymerase chain reaction' (fish-RFLP/PCR) on exposure to DEA/NO alone, however, exposure to HX/XO led to various mutations, suggesting that co-generation of NO and superoxide was responsible for inducing the observed point mutation. DEA/NO potentiated the ability of HX/XO to induce lipid peroxidation as well as DNA single- and double-strand breaks under these conditions, while 0.6 mM DEA/NO in the absence of HX/XO had no significant effect on these parameters. The results show that a point mutation seen at high frequency in certain common human tumors can be induced by simultaneous exposure to reactive oxygen species and a NO source.

Phylogeography of competing sexual and parthenogenetic forms of a freshwater flatworm: patterns and explanations

Background: Models of the maintenance of sex predict that one reproductive strategy, sexual or parthenogenetic, should outcompete the other. Distribution patterns may reflect the outcome of this competition as well as the effect of chance and historical events. We review the distribution data of sexual and parthenogenetic biotypes of the planarian Schmidtea polychroa. Results: S. polychroa lives in allopatry or sympatry across Europe except for Central and North-Western Europe, where sexual individuals have never been reported. A phylogenetic relationship between 36 populations based on a 385 bp fragment of the mitochondrial cytochrome oxidase I gene revealed that haplotypes were often similar over large geographic distances. In North Italian lakes, however, diversity was extreme, with sequence differences of up to 5% within the same lake in both sexuals and parthenogens. Mixed populations showed "endemic" parthenogenetic lineages that presumably originated from coexisting sexuals, and distantly related ones that probably result from colonization by parthenogens independent from sexuals. Conclusions: Parthenogens originated repeatedly from sexuals, mainly in Italy, but the same may apply to other Mediterranean regions (Spain, Greece). The degree of divergence between populations suggests that S. polychroa survived the ice ages in separate ice-free areas in Central, Eastern and Southern Europe and re-colonised Europe after the retreat of the major glaciers. Combining these results with those based on nuclear markers, the data suggest that repeated hybridisation between sexuals and parthenogenetic lineages in mixed populations maintains high levels of genetic diversity in parthenogens. This can explain why parthenogens persist in populations that were originally sexual. Exclusive parthenogenesis in central and western populations suggests better colonisation capacity, possibly because of inbreeding costs as well

The whereabouts of an ancient wonderer: Global phylogeography of the solitary ascidian Styela plicata

Genetic tools have greatly aided in tracing the sources and colonization history of introduced species. However, recurrent introductions and repeated shuffling of populations may have blurred some of the genetic signals left by ancient introductions. Styela plicata is a solitary ascidian distributed worldwide. Although its origin remains unclear, this species is believed to have spread worldwide by travelling on ship's hulls. The goals of this study were to infer the genetic structure and global phylogeography of S. plicata and to look for present-day and historical genetic patterns. Two genetic markers were used: a fragment of the mitochondrial gene Cytochrome Oxidase subunit I (COI) and a fragment of the nuclear gene Adenine Nucleotide Transporter/ADP-ATP Translocase (ANT). A total of 368 individuals for COI and 315 for ANT were sequenced from 17 locations worldwide. The levels of gene diversity were moderate for COI to high for ANT. The Mediterranean populations showed the least diversity and allelic richness for both markers, while the Indian, Atlantic and Pacific Oceans had the highest gene and nucleotide diversities. Network and phylogenetic analyses with COI and ANT revealed two groups of alleles separated by 15 and 4 mutational steps, respectively. The existence of different lineages suggested an ancient population split. However, the geographic distributions of these groups did not show any consistent pattern, indicating different phylogeographic histories for each gene. Genetic divergence was significant for many population-pairs irrespective of the geographic distance among them. Stochastic introduction events are reflected in the uneven distribution of COI and ANT allele frequencies and groups among many populations. Our results confirmed that S. plicata has been present in all studied oceans for a long time, and that recurrent colonization events and occasional shuffling among populations have determined the actual genetic structure of this species.

Bartonella apis sp. nov., a honey bee gut symbiont of the class Alphaproteobacteria.

Here, we report the culture and characterization of an alphaproteobacterium of the order Rhizobiales, isolated from the gut of the honey bee Apis mellifera. Strain PEB0122T shares >95 % 16S rRNA gene sequence similarity with species of the genus Bartonella, a group of mammalian pathogens transmitted by bloodsucking arthropods. Phylogenetic analyses showed that PEB0122T and related strains from the honey bee gut form a sister clade of the genus Bartonella. Optimal growth of strain PEB0122T was obtained on solid media supplemented with defibrinated sheep blood under microaerophilic conditions at 35-37 °C, which is consistent with the cultural characteristics of other species of the genus Bartonella. Reduced growth of strain PEB0122T also occurred under aerobic conditions. The rod-shaped cells of strain PEB0122T had a mean length of 1.2-1.8 μm and revealed hairy surface structures. Strain PEB0122T was positive for catalase, cytochrome c oxidase, urease and nitrate reductase. The fatty acid composition was comparable to those of other species of the genus Bartonella, with palmitic acid (C16 : 0) and isomers of 18- and 19-carbon chains being the most abundant. The genomic DNA G+C content of PEB0122T was determined to be about 45.5 mol%. The high 16S rRNA gene sequence similarity with species of Bartonella and its close phylogenetic position suggest that strain PEB0122T represents a novel species within the genus Bartonella, for which we propose the name Bartonella apis sp. nov. The type strain is PEB0122T ( = NCIMB 14961T = DSM 29779T).

Alcatrão ou creosoto de eucalipto na produção de adesivos fenólicos para colagem de madeira

This study has shown that Eucalyptus tar and creosote can be used in phenolic adhesive formulations (resols) for wood products bonding. Some adhesives were prepared substituting 0; 17.7; 35.0 and 67.0% of the phenol by anhydrous tar and 0; 15.0 e 28.5% by creosote. In gluing Brazilian pine veneers, eucalypt tar and creosote based adhesives required longer pressing times for curing than conventional phenol-formaldehyde adhesives. By using 13C NMR, the number of carbons in side chains and hydroxyl, carbonyl, carboxyl and methoxyl groups related to 100 aromatic rings could be estimated in tar and creosote. In creosote, after reaction with excess formaldehyde in alkaline medium, only 0,28 hydroxymethyl groups was detected per phenolic ring. This low amount of hydroxymethylation explains the lack of reactivity in curing observed when creosote was introduced in a standard adhesive formulation.

High voltage discharge for degradation of organic contaminants in water

The pulsed dielectric barrier discharge (PDBD) and pulsed corona discharge (PCD) were compared for their efficiency to degrade phenol in water solution. Results show that PCD has higher efficiency than PDBD to degrade phenol. When initial pH of water solution was elevated, phenol degradation in the PCD reactor was significantly enhanced, although no considerable effect was seen in the PDBD reactor. The PCD reactor was also able to degrade lignin significantly, both in synthetically prepared solution and in pulp and paper mill wastewater. Water temperature did not affect phenol degradation; however, lignin was better oxidized at lower temperature.

Nitração do fenol, um método em escala semi-micro para disciplina prática de 4 horas

A procedure for the nitration of phenol in a semi-micro scale, followed by separation of the formed orto- and para-nitrophenol isomers by column chromatography, is described. All the experiment, including determination of the melting point of the isolated products, require a period of 4 hours, and it is suitable for organic chemistry laboratory undergraduate courses.